1. Field of the Invention
The invention relates to a field chopper with an internal combustion engine, which is connected to drive a crop intake device, a chopping device, and a feeding device designed for transporting crops from the crop intake device to the chopping device, and with a controller, which is designed for engaging and disengaging the drive of the crop intake device and to an operator input device, which enables input for setting the chopping operation. The invention also relates to a method for operating the field chopper.
2. Related Technology
Field choppers are used in agriculture to cut or collect crops from a field by means of a crop intake device, to feed these crops via feeding device to a chopping device, usually a chopping cylinder or a disk pate chopper, in order to chop these crops and to discharge them, usually after being accelerated by means of a blower, through an ejection bend adjustable in position onto a transport vehicle. In most cases, the harvested plants are used as silage fodder for feeding animals.
The crop intake device, the feeding device, and also the chopping device are driven by an internal combustion engine. The cutting length is defined by the usually variable speed of the feeding device and the rpm of the chopping device dependent on the rpm of the internal combustion engine. In the state of the art, mechanical gears that can be switched in steps, hydraulic drives (U.S. Pat. No. 5,901,535), or planetary gears, which comprise hydraulically and mechanically driven elements (U.S. Pat. No. 6,052,978) are used for selecting the cutting length. Consequently, the speed of the feeding device can be changed by operating input or based on sensor values (U.S. Pat. No. 7,189,160). The crop intake device is driven by a remote-controllable coupling (see U.S. Pat. No. 6,810,649), which enables an operator to set the crop intake device in motion before the beginning of the chopping operation.
When the coupling of the crop intake device is disengaged, often so-called overlengths, i.e., cut material with a cut length that is greater than the desired or set cutting length, are produced. These overlengths are produced due to the fact that the crops still present in the feeding device at the beginning are not properly gripped by the chopping device and therefore are not ejected with a reduced size as a whole or at least not at the desired measure. In addition, the couplings for the feeding device and the crop intake device are relatively strongly loaded, when these are engaged and suddenly set to their desired speed.
In the state of the art, various automated mechanisms for engaging a harvesting header (U.S. Pat. No. 6,073,429) or disengaging the drive of a field chopper (U.S. Pat. No. 5,527,218), as well as devices for setting the rpm of an internal combustion engine of a field chopper have been described (DE 101 10 232 A), which, however, cannot solve the described problem.
As seen from above, there remains a need for a field chopper in which the production overlength is reduced during the starting of the chopping operation.